It ain't over until it is over.

Hindustan Times via Getty ImagesCongress President Rahul Gandhi addresses the media after B.S. Yeddyurappa resigned as Karnataka Chief Minister, at AICC, on May 19, 2018 in New Delhi, India.

The Congress Party cobbled together a coalition to keep the Bharatiya Janta Party from power in Karnataka, but the battle for the southern state is not over yet.

Even as details of its alliance with the Janata Dal (Secular) are fleshed out, the Congress high command remains on tenterhooks, fearing a last-minute attempt by the BJP to poach its lawmakers, trigger President's Rule, and force a re-election.

JD(S) president H.D. Kumaraswamy will take oath as chief minister on Wednesday, leaving a window for the BJP to undermine the fledgling alliance.

"The BJP is capable of anything. They can try to impose President's Rule. We have to be ready," said a Congress official, speaking on condition of anonymity.

On Saturday, the BJP failed to prove its majority in the Karnataka Assembly. B.S. Yeddyurappa, was forced to resign, less than 48 hours after he was sworn-in as the chief minister.

With 78 and 37 seats respectively, the Congress and the JD(S) have the numbers to form the government.

There are some within the Congress who feel that Kumaraswamy should have taken oath today, and a date for the floor test should have been determined post-haste.

Instead, Kumaraswamy postponed his swearing in ceremony from May 21 to 23. The JD(S) president said that he did not want to take oath on Rajiv Gandhi's death anniversary.

Observers believe that the former prime minister's death anniversary coupled with "astrological" reasons has led the postponement from May 21 to 23rd. There are many who regard Tuesday, May 22, as inauspicious.

Further, Kumaraswamy, following his meeting with Congress Party president Rahul Gandhi and his mother, Sonia Gandhi, in Delhi, is expected to head to Tirupati to pay his respects at the Sri Venkateswara temple. His father and founder of the JD(S), H.D. Deve Gowda, visited the same temple on his birthday, last week.

Kumaraswamy will then head to Bengaluru to take oath.

Meanwhile, Congress lawmakers remain sequestered at the Hilton and Le Meridien in Bengaluru, but keeping the flock together remains a challenge.

Last week, the Congress almost lost two of its lawmaker, Anand Singh and Pratapgouda Patil, who were holed up at the Goldfinch hotel instead of sticking with their colleagues.

Congress sources said that two MLAs decided to stay with the party only after the Supreme Court drastically reduced the BJP's time for proving its majority from 15 days to less than 48 hours. In other words, they decided to say after it became clear that the BJP would not be able to rope in the seven lawmakers it needed to form the government.

Not only does the BJP have more time, Congress leaders believe that BJP president Amit Shah is not one to give up.

Meanwhile, Congress Party lawyers remain on standby to rush to the Supreme Court if the BJP has another go at taking power in Karnataka. "Prevention is better than cure," a Congress source said.